Postgres：将 JSON 数据扩展到列和行

Question

我有一个 SQL 表格，其中包含 JSON 格式的列。以下是 SQL 查询输出的示例：

我需要此表中的每一行将 JSON 对象和值扩展为包含相应数据的新列。

第一行的示例是一个名为“rate”的新列，其值将为“0.25”，而对于第二行，应创建名为“from”、“to”、“fixed”的其他列以及相应的值应存储在两个单独的行中，保持其余信息与查询本身相同。

这里的复杂性是数据集上的每一行都有不同的信息存储在“数据值”列（JSON 数据）中。

有什么方法可以使用查询或任何其他方法来执行此操作吗？

编辑： 添加我的 SELECT 语句以供参考，为每个对象添加一个新列，但这不适用于数组。

    SELECT
    port.id                                                                         as "Port ID",
    port.name                                                                       as "Port Name",
    country.name                                                                    as "Country",
    port_expense.id                                                                 as "Port Expense ID",
    port_expense.name::text                                                         as "Port Expense",
    terminal.id                                                                     as "Terminal ID",
    terminal.name                                                                   as "Terminal Name",
    berth.id                                                                        as "Berth ID",
    berth.name                                                                      as "Berth Name",
    port_expense_formula_data.name                                                  as "Data Name",
    port_expense_formula_data.value                                                 as "Data Value"
    -- port_expense_formula_data.value::jsonb->>'from'                                 as "From", 
    -- port_expense_formula_data.value::jsonb->>'to'                                   as "To",
    -- port_expense_formula_data.value::jsonb->>'unmoor'                               as "Unmoor",
    -- port_expense_formula_data.value::jsonb->>'var'                                  as "Var",
    -- port_expense_formula_data.value::jsonb->>'tariff'                               as "Tariff",
    -- port_expense_formula_data.value::jsonb->>'rate'                                 as "Rate",
    -- port_expense_formula_data.value::jsonb->>'lumpsum'                              as "Lumpsum",
    -- port_expense_formula_data.value::jsonb->>'max'                                  as "Max",
    -- port_expense_formula_data.value::jsonb->>'min'                                  as "Min",
    -- port_expense_formula_data.value::jsonb->>'charge'                               as "Charge",
    -- port_expense_formula_data.value::jsonb->>'day'                                  as "Day",
    -- port_expense_formula_data.value::jsonb->>'night'                                as "Night"

以及输出示例：

Answer 1

首先使用 jsonb_array_elements 展平表格以解除 JSON 数组的嵌套，并使用 横向连接 以便为每个数组元素生成一行。

SELECT
 port.id                         as "Port ID",
 port.name                       as "Port Name",
 country.name                    as "Country",
 port_expense.id                 as "Port Expense ID",
 port_expense.name::text         as "Port Expense",
 terminal.id                     as "Terminal ID",
 terminal.name                   as "Terminal Name",
 berth.id                        as "Berth ID",
 berth.name                      as "Berth Name",
 port_expense_formula_data.name  as "Data Name",
 port_expense_formula_data.value as "Data Value"
  j->>'from'    as "From", 
  j->>'to'      as "To",
  j->>'unmoor'  as "Unmoor",
  j->>'var'     as "Var",
  j->>'tariff'  as "Tariff",
  j->>'rate'    as "Rate",
  j->>'lumpsum' as "Lumpsum",
  j->>'max'     as "Max",
  j->>'min'     as "Min",
  j->>'charge'  as "Charge",
  j->>'day'     as "Day",
  j->>'night'   as "Night" 
from <your joined tables here> 
cross join lateral 
  jsonb_array_elements(port_expense_formula_data.value::jsonb) j;